// HTMLParser Library $Name: v1_6 $ - A java-based parser for HTML
// http://sourceforge.org/projects/htmlparser
// Copyright (C) 2004 Somik Raha
//
// Revision Control Information
//
// $Source: /cvsroot/htmlparser/htmlparser/src/org/htmlparser/tags/BaseHrefTag.java,v $
// $Author: derrickoswald $
// $Date: 2005/04/10 23:20:45 $
// $Revision: 1.40 $
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//

package org.htmlparser.tags;

import org.htmlparser.lexer.Page;
import org.htmlparser.nodes.TagNode;
import org.htmlparser.util.ParserException;

/**
 * BaseHrefTag represents an &lt;Base&gt; tag. It extends a basic tag by
 * providing an accessor to the HREF attribute.
 */
public class BaseHrefTag extends TagNode {
	/**
	 * The set of names handled by this tag.
	 */
	private static final String[] mIds = new String[] { "BASE" };

	/**
	 * Create a new base tag.
	 */
	public BaseHrefTag() {
	}

	/**
	 * Return the set of names handled by this tag.
	 * 
	 * @return The names to be matched that create tags of this type.
	 */
	public String[] getIds() {
		return (mIds);
	}

	/**
	 * Get the value of the <code>HREF</code> attribute, if any.
	 * 
	 * @return The <code>HREF</code> value, with the leading and trailing
	 *         whitespace removed, if any.
	 */
	public String getBaseUrl() {
		String base;

		base = getAttribute("HREF");
		if (base != null && base.length() > 0)
			base = base.trim();
		base = (null == base) ? "" : base;

		return (base);
	}

	/**
	 * Set the value of the <code>HREF</code> attribute.
	 * 
	 * @param base
	 *            The new <code>HREF</code> value.
	 */
	public void setBaseUrl(String base) {
		setAttribute("HREF", base);
	}

	/**
	 * Perform the meaning of this tag. This sets the base URL to use for the
	 * rest of the page.
	 * 
	 * @exception ParserException
	 *                If setting the base URL fails.
	 */
	public void doSemanticAction() throws ParserException {
		Page page;

		page = getPage();
		if (null != page)
			page.setBaseUrl(getBaseUrl());
	}
}
